In general, this invention relates to medical devices and methods. In particular, the instant invention relates to an improved device for the removal of tissue or foreign bodies from the body. One particular use of this improved device is removal of obstructions from the tubular channels of the body. These obstructions are usually blood clots (thrombi) or other byproducts of occlusive vascular disease (e.g. plaque) or even instruments/implants lost by the physician during an intervention including but not limited to wires, stents, staples, components, embolic coils, etc. Further, the removal of matter from non-vascular channels is disclosed. Even further, the instant invention can be used for the removal of tissue including but not limited to tissue biopsies, cancerous, necrotic, infected, or other diseased tissue from solid or semi-solid tissue.
Occlusive vascular disease is a common ailment in people resulting in enormous costs to the health care system. Blood clots are the most common type of occlusion. Removal of clots from the body has been studied for several years and many techniques (devices and methods) have been studied and practiced. One of the more common techniques is one referred to as embolectomy. Embolectomy is a treatment whereby the clot is removed from the body as opposed to being dissolved and then reabsorbed. Another alternative is thrombolysis. As the name indicates, this is lysing (eating) of the thrombus (blood clot). Usually this requires a significant amount of potentially dangerous and always expensive drug that is injected into the vasculature. The drug delivery is sometimes aided with special catheters, which may increase efficacy, but certainly increase cost. The deposit of sinuous plaque (arteriosclerosis) to the inner wall of arteries usually precedes clot formation. Several expensive devices (dilatation balloons, stents, mechanical cutters, etc.) have been introduced to fight this vascular occlusive disease, but none of which has proven to be the xe2x80x98magic bulletxe2x80x99 to treat this ubiquitous disease. Because of the various problems with all of the techniques and approaches to solving this medical condition, there exists no particular method or device that is considered the most accepted mode of treatment.
Unfortunately, cancer too is a common ailment resulting in over 1,500 deaths every day in the U.S. (550,000 every year). Therapy modalities for cancer are plentiful and continued to be researched with vigor. Still, the preferred treatment continues to be physical removal of the cancer. When applicable, surgical removal is preferred (breast, colon, brain, lung, kidney, etc.). Surgical removal is often extremely invasive and efforts to remove cancerous tissue in a less invasive way continue, but have not yet been perfected. The only cure for cancer continues to be early diagnosis and subsequent early treatment. As cancer therapies continue at an earlier stage of diagnosis, the cancerous tissue is smaller and smaller. Early removal of these smaller cancers demand new techniques for removal and obliteration that are less invasive. The instant invention describes new devices for less invasive cancer therapy. There are many techniques and devices known in the art for removing blockages in the vascular system and other passageways of the human body as well as removing other diseased tissue.
There is a continuing need for improved devices to meet at least the following objectives.
The first objective is to reduce cost. This is particularly important in recent years where it is clear for safety and sanitary reasons that these will be single use devices. A device, even though it performs a function in some improved manner, will not be widely used if it is considerably more costly than the alternatives available.
A second objective is to provide a device that is simple to use and in a very real sense simple to understand. This will encourage its adoption and use by medical personnel. It will also tend to keep cost low.
The third objective is to provide a device that entails a procedure with which the medical profession is familiar so that the skills that have been learned from previous experience will continue to have applicability.
A fourth objective relates to the effectiveness and thoroughness with which the biological tissue or foreign body is removed. With regard to biological tissue removal, it is important that an optimum amount of the mater be removed; recognizing that no device is likely to provide one hundred percent optimization.
A fifth objective concerns safety; a matter which is often so critical as to trump the other considerations. It is important to avoid unnecessary tissue trauma. In the case of using the present invention or its similar inventions in the tubular channels of the body, it is critically important to avoid breaking up matter in a fashion that leads to flushing elements of the blockage throughout the body involved. The same may be true for removal of diseased tissue removal, certainly in the case of removal of cancerous tissue.
There are trade-offs in design considerations to achieve the above five interrelated objectives. Extreme simplicity and a very simple procedure might overly compromise safety. Addressing all of these considerations calls for some trade-off between the objectives.
Accordingly, a major object of this invention is to provide an improved removal device that achieves the objectives of reduced cost, enhanced simplicity, a standard procedure, high effectiveness and a high degree of safety. Most particularly, it is an object of this invention to achieve these objectives with an enhanced trade-off value for the combined objectives.
For these reasons, it is desirable to provide an improved device that may circumvent some of the problems associated with previous techniques. This improved medical device provides a new configuration that will eliminate some of those problems and methods for their use, which facilitate removal of vascular obstructions in the operating room or interventional suite.
In brief, one embodiment of this invention is particularly adapted to the removal of blockages in vascular channels (biologic or synthetic) of the body. That embodiment combines an expanding channel catheter and a support wire having an occlusion-engaging element.
The support wire may extend through the expandable channel device or catheter, through or around the occlusion and at its distal end has an annular braided element attached thereto. The support wire is a dual element support wire having a core and an annular shell that slides on the core. The distal end of the core is attached to the distal end of the annular braided element and the distal end of the shell is attached to the proximal end of the annular braided element. Thus movement of the core and shell relative to one another moves the braided element from a radially retracted position which is useful for insertion through the catheter to a radially expanded position which expands it to the sidewall of the channel. When the annular braided element is in its radially compressed (smaller diameter) state, it can be passed through or around the occlusion together with the rest of the wire to reside on the distal end of the occlusion. When the braided element is expanded and moved proximally (that is, in a retrograde fashion), it will engage the occlusion and force the occlusion into the catheter. Alternatively, no motion of the engaging element may be required if aspiration is applied. In this case, the engaging expandable channel device acts as a seal to prevent the suction from aspiration to remove much material beyond its point of deployment in the channel. Further, no motion of the distal engaging element is required if the expandable engaging element is moved distally toward the occlusion and thusly engulfs the obstruction by its forward motion and expandability.
The distal end of the catheter is proximal of the occlusion and contains an expandable blocking mechanism that extends radially from the distal end of the catheter to the wall of the graft or body passageway. This catheter expandable blocking element also has a radially retracted insertion state and a radially expanded blocking state. The expandable blocking element is similar in construction to the distal engaging element in that it is a tubular braid, which may or may not be covered by or integrated with a thin film or membrane.
This distal tubular braid of expandable channel device is usually bonded to the distal end of the catheter or an integral part of the catheter. Pushing the assembly forward where it will meet resistance to the obstruction actuates the expandable characteristic of the expandable engaging element. Alternatively, there may be a mandril or drawstring that may cause the tubular braid to expand. In this case, the distal blocking element is expanded in a similar fashion. In this radially expanded state, the expandable engaging element and its film (if desired) blocks the annulus around the catheter so that the occluded blood or other obstruction which is being removed is forced into the catheter where it is aspirated, obliterated or otherwise removed.
The instant invention also describes another use of the same device of the instant invention with minor changes. In this case, the expandable tubular braid may be used as a tissue removal device as opposed to an obstruction removal device. In other words, the instant invention could be used for harvesting vein grafts, removal of plaque from arteries taking biopsy samples, or removal of diseased tissue (i.e. cancerous or other disease) from solid or semi-solid tissue. In this case, the present invention would be pushed forward and when it reached an expanded diameter (either by design of the tubular braid, design of the entire expandable assembly or by tissue constraints) it would separate tissue via the wall of the expanded tubular device. This separation of tissue may be aided by other energy sources such as, but not limited to mechanical (cutting), thermal, electrical energies, etc. Once the desired amount of tissue is removed, the expandable tubular braid (with tissue remaining within its inner diameter) may be removed from the body. This removal may include pulling the expanded tubular braid element and thus putting it into a tensile configuration, where the tubular braided element will have a tendency to be elongated and consequently the diameter of the expanded device may be decreased depending upon the matter contained within as well as the physical constraints put on the device by its particular environment within the body.
The instant invention provides an improved device of the type having a shaft with a proximal end and a distal end. The improvement comprises configuring at least a distal portion of the shaft so that it can assume a shape(s) along its shaft (proximally, mid-section or distally) that will act as a TRAP or dragger. In the case of body channels or cavities, this trap mechanism(s) is moved along the lumen (artery, vein, intestine, stent, graft, or other hollow vessel or organ) and then past the obstruction or tissue (clot, plaque, or other obstruction). Once it is past the obstruction, the user (physician/technician) can actuate the trap mechanism(s) so that it is enlarged beyond its original size/diameter and aid in removing the obstruction using another novel, elongate expandable channel. This novel, expandable channel has the ability to start small but is easily enlarged when the obstruction or tissue meets the distal end of the device. Once the material located in at least the distal end of this expandable channel (and possibly farther into it) the expandable channel that is distal to the material may shrink down to the original diameter or close to it. In other words, this new channel acts like a snake swallowing a large piece of food that originally is larger than the snake""s throat or intestines. For that reason, this new channel will be referred to as PYTHON. This technique may be aided with other aids such as the addition of lytic agents, monoclonal antibodies, vibration, irrigation, aspiration, therapeutic ultrasound or other energies such as mechanical, electrical, magnetic, etc. or pharmaceutical therapy(s) that will aid with removal or obliteration of the material. MIS (Minimally Invasive Surgery) or LIS (Least Invasive Surgery) devices described herein such as catheters and guide wires, for example are the most common tools used by least invasive interventionalists today. These devices are available in a variety of shapes and sizes from 0.008-0.500xe2x80x3 diameters and from 6.0-80.0xe2x80x3 in length. In other respects, the catheters and guide wires or other device(s) of the instant invention will have the geometries, characteristics, and dimensions of those commonly employed for the intended purpose (e.g. introduction to a blood vessel (LIS) or surgical tissue removal (MIS). MIS and LIS are often interchanged in their usage. Usually LIS refers to catheters, guide wires, (and the like) that are used within the body, often within the channels of the body. MIS typically refers to videoscopic surgery where miniature cameras are used to accomplish surgery. However, because of the large crossover of the use of these terms, the inventors do not wish to limit the scope of the devices described herein when these terms are used.
The intellectual property regarding vascular obstruction removal is extensive. Some of the pertinent embolectomy and atherectomy descriptions are set forth in a number of issued U.S. patents, including U.S. Pat. Nos. 5,498,236, 5,380,273 and 5,713,848 by the inventor of the instant invention (Dubrul) as well as U.S. Pat. Nos. 4,762,130, 5,827,729, 5,476,450, 4,998,919, 5,772,674, 5,370,653, 5,733,294 4,762,130 5,443,454, 5,419,774, 5,112,347, 4,030,503, 5,653,684 and 3,978,863.
U.S. Pat. Nos. 5,498,236, 5,380,273 and 5,713,848 by the inventor of the instant invention (Dubrul) describe a Motion Catheter that is used for xe2x80x98the removal and dissolution of obstructions within the lumens of the bodyxe2x80x99. In these issued patents, Dubrul et al additionally discloses a filter/occluder that is similar to the TRAP mechanism disclosed heretofore. However, Dubrul describes the filter occluder specially to keep particulate (e.g. emboli) from travelling downstream and causing deleterious effects on the patient (e.g. stroke). U.S. Pat. No. 4,762,130 by Fogarty describes a spiral balloon for the removal of blood clots (thrombus). U.S. Pat. No. 5,653,684 describes a device that uses and expandable tubular braid on the distal end of a catheter, but with this device the inventor uses the device to crack atheromous plaque using radio frequency energy.
The intellectual property regarding cancer therapies and removal is extensive as well. Some of the pertinent cancer therapy descriptions are set forth in a number of issued U.S. patents, including U.S. Pat. Nos. 5,368,597, 5,769,794, 5,647,372, 5,465,731 and 5,443,472.
U.S. Pat. No. 5,368,597 describes a reclosable pouch retaining tissue. U.S. Pat. No. 5,769,794 discloses a bag for cancerous tissue removal. U.S. Pat. No. 5,647,372 describes a specimen retrieval pouch. U.S. Pat. No. 5,465,731 discloses a method and device for specimen retrieval. U.S. Pat. No. 5,443,472 describes a morcellator system for diseased tissue.
Further, the pending patent application by the inventor (Dubrul et al) of the instant invention, Ser. No. 60/074,183, is pertinent to the instant invention with regard to using the distal TRAP mechanisms as a Anchor and Tensioner as well as a Detachable Vessel Occluder.
Further U.S. Pat. No. 5,827,729 by Auth describes an aspiration thrombectomy catheter with an angled distal end to allow aspiration of blood clot into the catheter. Ruggio, in U.S. Pat. No. 5,476,450, discloses an apparatus for aspirating substances into a catheter also. U.S. Pat. No. 4,998,919 describes a catheter designed to infuse a lytic agent and aspirate the residual clot through a larger lumen. U.S. Pat. No. 5,772,674 describes a thrombectomy device which includes a delivery and receiving catheter having balloons at their distal ends. In addition, Cragg, in U.S. Pat. No. 5,370,653, describes a thrombectomy device with rotating brushes.